Uber has proven it will do anything to intimidate journalists, said Sarah Lacy, founder and editor of tech website PandoDaily and the subject of a public relations firestorm that has engulfed the car service company this week.

"Uber itself launched an investigation into practices of data mining on a journalist," Lacy said. "Everyone else sees a pattern of horrific behavior except the people profiting off of what's one of if not the most highly valued private companies in Silicon Valley. No one with a stake in this company will stand up to Travis Kalanick publicly or privately."

Uber denied the allegation that it it has investigated journalists.

"We have not, do not and will not investigate journalists," an Uber spokesperson told CNBC.

Emil Michael, Uber's vice president of business, singled out Lacy when he made comments suggesting the company should hire journalists to dig up dirt on reporters. The incident occurred at a recent dinner attended by the media and Uber CEO Kalanick.

In a series of tweets on Tuesday, Kalanick apologized and said Michael's comments did not represent the views of the company. Michael issued an apology on Monday, saying he thought the conversation was off the record.

Lacy said she did not believe the apologies were genuine. If the incident did not reflect an attitude within the company, Michael would have been fired, she added.

"The details that he gave and exactly how he was going to go after my family were incredibly detailed," Lacy said. "This was a plan he had formulated. This was not a man ranting at dinner."

Lacy accused Uber of putting together a team with a million-dollar budget to investigate her.

"When you do opposition research on someone, particularly with a million-dollar budget and a six-person team, it's not going Googling someone's name. It's going through their trash. It's following their kids on the way to school. It's having vans parked outside their house, all because I said things the company didn't like," said Lacy.

On Wednesday, actor and Uber investor Ashton Kutcher took to Twitter to defend the company, writing, "What is so wrong about digging up dirt on shady journalist?" in a stream of tweets.

"Ashton Kutcher has talked before about his issues with people going after his stepchildren. I guess when you're a movie star, that's a double standard," Lacy said.